Clinical and virological predictors of sustained response with an interferon-based simeprevir regimen for patients with chronic genotype 1 hepatitis C virus infection.

Simeprevir plus peg-interferon/ribavirin (PR) is approved to treat chronic hepatitis C (HCV) genotype 1 (GT1) and GT4 infection. This study aimed to assess baseline and on-treatment the factors predictive of sustained virologic response 12-weeks post-treatment (SVR12) in patients receiving 12 weeks of simeprevir plus PR followed by 12 or 36 weeks of PR. Data from participants in four studies (QUEST-1, QUEST-2, ATTAIN and PROMISE) were pooled to examine the efficacy and safety of simeprevir+PR in HCV GT1 patients. The predictive power of baseline variables for SVR12 was assessed using univariate and multivariate logistic regression models while the relationship between early (Week 4) on-treatment response and SVR12 was analyzed by GT1 subtype and treatment experience. Data for 1160 patients were analyzed (overall SVR12: 71%). Baseline factors predictive of SVR12 were: IL28B CC genotype, GT1a/Q80K-negative, treatment-naive/prior relapser, no cirrhosis, HCV-RNA <= 2,000,000IU/mL, albumin >42g/L, platelets >200x10(9)/L. Patients with HCV GT1b (86%), IL28B CC genotype (87%), and treatment-naive patients (83%) were predicted to achieve the highest SVR12 rates and rates of rapid virologic response. Week 4 early on-treatment response identified treatment-naive and prior relapse patients likely to achieve SVR12. Patients likely to respond to simeprevir+PR can be identified using baseline factors. Early on-treatment response predicts treatment success.